Rob R. wrote:It does when you have a decent puff-back...unless you sealed the seams.

I think "decent puff-back" is an oxymoron. All mine have been pretty offensive, if not actually indecent.But what you say makes sense. I never thought about crimp-up vs. crimp-down during a puff-back -- when it happens I generally just make the sign of the cross and then look to see if the glass has blown out of the door.